What makes a record collection "great"?

two things
first, if you think it is a great collection it is
second if it has what you want in it

Just like a library. A library will have within it "collections" that would be prized.
I have a large collection that is comprised of different genres. Depending on your tastes you may find that parts of my collection are "great". Some may find that jazz alongside country or psychedelia would make for a wierd, not great, collection. Collections within a collection, like a library.
Anyway, who cares if it's great if it pleases you, whetherit's 10LPs or 10,000LPs?!
;^)

A great record collection is the collection YOU enjoy listening to regardless of genre.

Dear Badboss429: I own thousands of LPs and from this point of view i can't say it is a great collection but I own around 300-350 LPs ( the other " thousands " are all full of " dust ". ) that when I hear any one I really enjoy the music.
These 300-350 ( maybe a little more ) are the ones that I usualy hear and from this point of view my LPs library is a great one.

When I hear/listen to these " great collection " LPs the only subject that exist is the music: no hardware, no VTA changes each side, no AZ changes, no ..., no..., etc, even no volume changes. These records are the ones that really " move " me.
In this " great collection " are different kind/genre of music and different kind of recordings: vintage, re-issues, audiophile ones, etc, etc.
These collection is " my music " is what I like and certainly is a great colletion only for me and no one else.

Till today in that collection are the Lp's that I want to have and till today I'm not looking for something special for that collection.
Of course that I don't know every recording out there and certainly there are several LPs that if I hear it ( for the first time ) some time will belong to my " great collection ".

+++++ " but no one has ever complimented me on having a great collection. " +++++

Badboss429 IMHO you don't need it. The best compliment about is the one that comes from your self!!!!

Regards and enjoy the music.
Raul.

Who Cares? I buy music I like and I listen to it with no concern of anyone's opinion but mine. It's my sandbox, my rules.